Balance-spring having elasticity increasing with rise in temperature.



UNITED STATES PATENT OFFICE.

CHARLES EDOUARD GUILLAUME, or snvnns, FRANCE, ASSIGNOR 'ro SOCIETE DESrumours nn'srmaux owns, or LA'CHAUX-D-E-FONDS, SWITZERLAND.

BALANCE-SPRING HAVING ELASTICITY INCREASING WITH RISE IN TEMPERATURE.

Patented Aug.4, 1914.

1,106,207. Specification of Letters Patent.

No Drawing. Application filed February 20, 1912. Serial No. 679,808.

To all whom it may concern: 3

Be it known that I, CHARLES EDOUARD GUILLAUME, doctor of philosophy andas-' sistant director of the International Oflice of 5 lVeights andMeasures, a citizen of the Swiss Republic, and resident of Sevres,Department of Seine-et-Oise, France, have invented new and usefulImprovements in Balance-Springs Having Elasticity Increasing with Risein Temperature, of which the following is a full, clear, and exactspecification.

For some years escapements for watches, clocks, etc., have been usedcomprising a balance wheel which is not cut and a spring of elasticityincreasing wit-h the temperature so that it compensates for thevariations of the inertia of the balance wheel with variations oftemperature. Hitherto there have been used for this purpose practicallyonly balance springs of nickel-steel containing 2728 per cent. of nickelas specified in United States Letters Patent 669,763 dated March 12,1901. This steel being very soft springs made of it have a very lowelastic limit and consequently are very easily deformed, especially ifthey are not made with great care; moreover, the soft character of thisalloy makes the construction of the cs- 30 capement and the operation ofregulating it very delicate. It follows that these escapements cannot beused for accurate watches intended for chronometric computations inobservatories.

This invention relates to a balance spring having elasticity increasingwit-h the rise of temperature, which possesses a high elastic limit.This result is obtained by making balance springs of an alloy of ironand 40 nickel containing from 2731 per cent. of nickel, 0.3 to 0.6 percent. of silicon, 0.3 to 0.6 per cent. of carbon, at least one metal ofthe sixth group of the classification of Mendeljefi, as for instance,chromium, molybdenum or tungsten and at least one metal of the fifthgroup of the said classification, as for instance, vanadium or tantalum,the said metals being each employed in a quantity of 0.2 to 4 per cent.in such a manner that the total amount of them and of the carbon andsilicon comprises between 3.5 to 10 per cent. of the whole alloy. Thealloy can also contain 1 to 4 per cent. of manganese, in which case thetotal amount of carbon, of silicon, of manganese and of the other metalsadded to the alloy of nickel and iron must always remain between 3.5 to10 per cent. of the whole alloy. When so made the balance spring has ahigh elastic limit and also the property of increasing in elasticity asthe temperature rises; consequently it may be used in the constructionof the escapement without risk of undergoing any deformation and lendsitself to the operation of regulating the escapement as easily as thesteel springs of ordinary escapements do.

By way of example the composition of an alloy for balance springsaccording to this invention is' given hereafter:

Nickel 30. 5 parts by wei ht, Ir0n 61.6

nganese 4 ,7 a Chromium 1. 8 n Vanadium 1.0 n Carbon 0. 6 a, siliC0n 5 na, a:

What I claim is: 1. A balance spring, of which the elasticity increaseswith the rise of temperature and with a high elastic limit consisting ofan alloy of iron and nickel containing between 27-31 per cent. of nickeland besides of small quantities of carbon and of silicon at least onemetal of the sixth group of the classification of Mendeljefl' and atleast one metal of the fifth group of the said classification, each ofthese metals being in such a proportion between 0.2 and 4 per cent. thatthe total amount of these metals and of the carbon and silicon in thealloy is between 3.5 and 10 per cent. of the whole alloy.

2. A balance spring of which the elasticity increases with-the rise oftemperature and which has a high elastic limit made from an alloy ofiron and nickel containing between 27-31 .per cent. of nickel andbesides of small quantities of carbon and of silicon and of 1 to 4 percent. of manganese at least one metal of the sixth group of theclassification of Mendeljefi' and at least one metal of the fifth groupof the said classification, each of these metals being in such aproportion between 0.2 and 4 per cent, that the total amount of thesemetals and of the carbon manganese and silicon in the alloy is between3.5 and 10 per cent. of the whole alloy. I

3. A balance spring, of which the elasticity increases with the rise oftemperature and which has high elastic limit consisting of an alloy ofiron and nickel containing between 27-31 per cent. of nickel and besidesof small quantities of carbon and of silicon chromium and a metal of'thefifth group of the classification of Mendeljefi, each of these metalsbeing "in such a proportion'between 0.2 and 4 per cent, that the totalamount of these metals and of the carbon and silicon in the alloy isbetween 3.5 and 10 per cent. of the whole alloy.

4. A balance spring of which the elastlcity increases with the rise oftemperature and which has a high elastic limit consisting of an alloy ofiron and nickel containingbetween 27 31 per cent. of nickel and besidesof small quantities of carbon and of silicon and of l to 2 per cent. ofmanganese chromium and a metal of the fifth group of the classificationof'Mendeljefl, each of these metals being in such -a proportion between0.2 and 4 per cent, that the total amount of these metals and of thecarbon, manganese and silicon in the alloy is between 3.5 and 10' percent. of the whole alloy.

5. A balance spring of which the elasticity increases with the rise oftemperature and which has high elastic limit consisting of an alloy ofiron and nickel containing between per cent, that the total amount ofthese metals and "of the carbon and silicon in the alloy is between 3.5and 10 per cent. of the whole alloy.

6. A balance spring. of which the elasticity increases with the rise oftemperature and 'WhlCh has high elastic limit consisting of an alloy ofiron and nickel containing between 2731 per cent. oi nickel and besidesof small quantities of carbon and of silicon and of 1 to 4 per cent.ofvmanganese, chromium and vanadium, each of these metals being in sucha proportion between 0.2 and 4 per cent, that the total amount of thesemetals and of the carbon, manganese and silicon in the alloy is between3.5 and 10 per cent. of the whole alloy.

In witness whereof I have hereunto signed my name this 7th day ofFebruary, 1912, in the presence of two subscribing witnesses.

5 CHARLES EDOUABD GUILLAUME.

Witnesses:

CHARLES ALBERT VUILLE, BARTL'EY F. Yos'r.

